In reply to markymark31:
It should work as normal when taken away from anything with an eletromagnetic source (phone/GPS/etc). As a rule I try not to store electrical items with my compass as they can get inverted polarity (north pointing to south/south to north) if the magnetic signal is strong enough (I have had this happen once, with what I think was my compass getting near a large speak, but I can't be sure), but I am probably being slightly paranoid about it if am an honest.
Craig.